The brain functions as the primary receiver, organizer, and distributor of information in the nervous system. To accomplish these tasks, the brain is made up of a complex network of neurons. Signals are transmitted between neurons via specialized connections called synapses. In the first few years of life, a child's brain can have as many as 15,000 synapses per neuron; however, the brain of the average adult has far fewer synapses per neuron. This is due to neuroplasticity, where some synapses are strengthened and others are eliminated over time due to the presence or absence of adequate stimulation. Neuroplasticity can occur as a result of learning, experience, and memory function, but may also occur as a result of damage to the brain. Such instances of neuroplasticity are often seen as improvements. However, neuroplasticity does not always cause positive changes; sometimes, these neuroplastic changes can lead to detrimental effects on the brain and behavior, such as misperceptions, pain, maladaptive behavior, or other indications of brain dysfunction.